hockeydude

So as many of you know, i have been having some cooling system troubles. I have replaced many hoses, and have a new expansion tank and thermoswitch. the system does not leak from what i can see (even after a 120 mile drive). The waterpump and thermostat both have less than 300 miles on them.

But my 951 is runing at the high white temperature mark ALL OF THE TIME! It never goes above, but this is really annoying! For the last 3 years, this car has run around that first white mark, so i know that this high-temp deal is not normal for my particular car...

After a drive to mid-ohio yesterday with some other 951's, an infared thermometer showed similair head temps, but my car's expansion tank was 30 degrees hotter(right around 200*) than my friends...(all 3 of the 951's compared are setup nearly identical)

I have blown into the radiator to make sure that it's not clogged, have new bleeder screws, do not see any signs of a Head-gasket failure, and to the best of my knowledge, the cooling system is bled sufficiently.


So why is my car running so much warmer?! Faulty Thermostat?

Van

Good question - I'm finding the same with my car. Do you know if you changed from an 80* to 83* thermostat? My car has an 83* - I'm changing expansion tanks and putting in an 80*. We'll see if it makes a difference.

F18Rep

I'm thinkin you'll like it, the question is ... is there a downside? And what if the turbo tstat doesn't match the main tstat, is that a problem?...Bruce

pa944red

I had a similar issue.

Check the connection at the temperature sensor on the engine. Mine was corroded. Once I cleaned it up and made the connection solid, my guage stayed just above the first mark. After replacing the battery cables the guage was rock solid on the line.

Hope that helps.
Tom

fbgh2o

This is a good idea. (I had the same issue - although mine was reading too low)

Also, I had a number of threads on this about a year ago. Couple of thoughts:

(1) Are the fans operating correctly? (or at all)
(2) I had an issue with my thermostats (2) being bad from the factory. They would not open until over 90C.

Van

hmm... maybe I should check this.

I boiled a pot of water, put the thing in, and it opened up. But, of course, didn't measure the water temp.

I might as well before I put it all together!

milodorr

hockeydude,

At the risk of piling on, I'll second/third pa944red's and fbgh2o's suggestion. I battled this maddening problem for a quite a while before solving it by simply cleaning up the gauge contact. You'll have to remove some stuff to get to it. If you want some confirmation of the diagnosis before doing that, you might try measuring the head temp with an infrared thermometer to see if the temps being reported by the gauge are real or not.

-Milo

milodorr

hockeydude,

My apologies. This will teach me to respond to original posts rather than responses to posts. I understand you've already investigated your problem with an infrared thermometer.

Given what you've said and what you've already replaced, I'm now thinking radiator. When you said you've "blown through" it, did you literally mean blown air through the inside, or just, say, shot water through the fins to clean them out (a good idea in any case). Even if it's the former, I'm not sure how that would preclude a partial blockage somewhere.

-Milo

Willard Bridgham 3

Start with the radiator. Take it out and have it steam cleaned, inside and out.

What do you know about the water pump and thermostat?

SprintStar

Has your car got AC? Is your condensor clogged? I went the whole hog of getting new water pump, new radiator, new tank, new thermostat, new... Well, you get the picture.

I put a light in the engine bay and couldn't see light from the licence plate. Enough said. Out came the condensor with years and years of crud. Runs cool now. *fingers crossed*

Sprint.

Thom

I had a similar issue on my S2 caused by using a Laso thermostat instead of a Wahler, Wahler being the OEM fitment.

With the Laso unit the temp would stay half way between two marks but jump to the second line as soon as slowing down (jams, city driving).
With Wahler the temp would stay just above the first line and increase slowly when slowing down.

I tested both thermostats in boiling water and noticed the Laso unit opened less that then Wahler as its springs had more splines, resulting in a lower flow than with the Wahler.

Chris White

I am with Willard - how old is your waterpumnp?
BTW - in a 'normally' running 951 the coolant from the block does not make it into the expansion tank, the coolant from the electric turbo pump in usually the only coolant to get circulated through the expansion tank.

alex_cristocea

had a similar issue. Change the thermostat wit a lower temperature one. If you cand find one to open at 75-80 you can buy an audi 100 or audi 200 2.3 petrol. it's the same thermostat and you can find a wid range. Also you may consider changing the thermoswich fan with a lower temp one. The original 92-102 seems a little bit high for this cars. You can also clean the radiator. It cand return good results.

hockeydude

UPDATE!! I put a new 80*C thermostat in yesterday, along with a good flush ofthe system, distiller water, and some new coolant. This fixed my running hot issue, and the car again runs at tv first white tic...

As for the old thermostat...well... There's a reason why I don't get parts anymore from the local place... 87*C!

Thanks again to all that have helped me troubleshoot this!!

sebastian944

That's interesting, i'm sure i read posts that the low temp thermostat is the wrong one to buy. I don't remember now if it was because the fans and electric pump will come on early with an 80*C thermostat or the other way around. I specifically remember a rennlister from Las Vegas, NV comment on this.